Carboniferous System. 47 



proach fossils, which, in Europe, occur in the Silurian rocks. 

 Everything, then, leads us to refer this great quartzose depo- 

 sit to the palaeozoic formations. Its connection with the slate 

 formation which it covers, does not allow of its being removed 

 far from it ; and as the union of these slates with the Silu- 

 rian system seems to us reasonable, the reference of the great 

 quartzose deposit to the Devonian system or old red sand- 

 stone, appears to us the most judicious that can be made in 

 the present state of our knowledge. 



Carboniferous System. — The system of Devonian quartzose 

 sandstones is succeeded in Bolivia, and in some other parts of 

 South America, by another series of beds which M. d'Orbigny 

 refers to the carboniferous system. This new series of beds 

 consists in its lower part of compact grey limestone contain- 

 ing siliceous nodules, analogous to the carboniferous limestone 

 of English authors, and perfectly similar to that of Vise near 

 Liege, and to the limestones of many parts of the British 

 Islands. This limestone has been more particularly noticed 

 in the islands of Quebaya (Lake of Titicaca.) At other points 

 (at Yarbichambi), the lower parts of the same system pre- 

 sent compact, yellow, or rose- coloured calcareous sandstones. 

 These beds contain numerous fossils. In the islands of Quebaya, 

 and at Yarbichambi, they are succeeded in conformable stra- 

 tification by red non-argillaceous quartzose sandstones, which 

 are friable and destitute of fossils. It is from observations 

 made on these two points that M. d'Orbigny has concluded, 

 that he may refer to the carboniferous series all the friable 

 rose-coloured argillaceous sandstones which repose on the 

 Devonian system, and which are inferior to the presumed 

 Triassic variegated clays. 



The system of beds, of which we have just indicated the 

 composition, presents itself at a great number of points, and 

 is distributed throughout nearly the whole breadth of the 

 American continent. The Morro of Arica, washed by the 

 waves of the Pacific Ocean, is composed, at its base, of a 

 limestone, which seems to belong to the carboniferous epoch, 

 judging from the impressions of a productus contained in one 

 of the specimens collected by M. d'Orbigny, and from nume- 

 rous organic remains observed by him at the locality. This 



